Consider a system consisting of \(k\) instances of a resource \(R\), being shared by 5 processes. Assume that each process requires a maximum of two instances of resource \(R\) and a process can request or release only one instance at a time. Further, a process can request the second instance of the resource only after acquiring the first instance.
The minimum value of \(k\) for the system to be deadlock-free is __________. (answer in integer)